Shale hydration inhibition agent and method of use

Abstract

A water-base fluid for use in drilling wells and other drilling operation includes a shale which swells in the presence of water. The fluid preferably includes: an aqueous based continuous phase, and a shale hydration inhibition agent having the formula:in which R and R' are alkylene groups having 1 to 6 carbon atoms and x is a value from about 1 to about 25. The Y group should be an amine or alkoxy group, preferably a primary amine or a methoxy group. The shale hydration inhibition agent should be present in sufficient concentration to reduce the swelling of the shale. The fluid may be used for formulating drilling fluids such as invert emulsion drilling muds or clear brine drilling fluids. The fluid may also be used in the slurrification and disposal of drill cuttings that contain water swellable clays or shales.

What is claimed is:  
     
       1. A composition comprising: 
       an aqueous based continuous phase;  
       a swellable shale material; and  
       a shale hydration inhibition agent having the formula:  
       
         
           H 2 N—R—{OR′} x —Y  
         
       
       wherein R and R′ are alkylene groups having 1 to 6 carbon atoms and  
       x is a value from about 1 to about 25, and  
       and Y is an amine or alkoxy group  
       wherein the shale hydration inhibition agent is present in sufficient concentration to reduce the swelling of the shale.  
     
     
       2. The composition of  claim 1  wherein x has an average number between about 1 and about 10. 
     
     
       3. The composition of  claim 1  wherein R and R′ are alkylene groups having a different number of carbon atoms or a same number of carbon atoms. 
     
     
       4. The composition of  claim 1  wherein the shale hydration inhibition agent being further characterized by low toxicity and compatibility with anionic drilling fluid components. 
     
     
       5. The composition of  claim 1  wherein the aqueous based continuous phase is selected from: fresh water, sea water, brine, mixtures of water and water soluble organic compounds and mixtures thereof. 
     
     
       6. The composition of  claim 1  further comprising a fluid loss control agent selected from the group consisting of organic polymers, starches, and mixtures thereof. 
     
     
       7. The composition of  claim 1  further comprising an encapsulating agent selected from the group consisting of organic and inorganic polymers and mixtures thereof. 
     
     
       8. The composition of  claim 1  wherein shale hydration inhibition agent is selected from: 
       
         
           H 2 N—CH 2 CH 2 —O—CH 2 CH 2 —NH 2    
         
       
       
         
           H 2 N—CH 2 CH 2 CH 2 —O—CH 2 CH 2 —O—CH 2 CH 2 CH 2 —NH 2    
         
       
       
         
           NH 2 —CH 2 —CH(CH 3 )—(O—CH 2 —CH(CH 3 )) 8 —O—CH 2 —CH 2 —OCH 3    
         
       
       and mixtures of these. 
     
     
       9. A water-base fluid for use in the slurrification and injection of drill cuttings into a subterranean formation for disposal, the fluid comprising 
       an aqueous based continuous phase, and  
       a shale hydration inhibition agent having the formula:  
       
         
           H 2 N—R—{OR′} x —Y  
         
       
       wherein R and R′ are alkylene groups having 1 to 6 carbon atoms and  
       x is a value from about 1 to about 25, and  
       and Y is an amine or alkoxy group  
       wherein the hydration inhibition agent is present in the drilling fluid in sufficient concentrations to reduce the swelling of shale clay that may be contained in the drill cuttings.  
     
     
       10. The fluid of  claim 9  wherein the aqueous based continuous phase is selected from: fresh water, sea water, brine, mixtures of water and water soluble organic compounds with mixtures thereof. 
     
     
       11. The fluid of  claim 10  wherein the drilling fluid further contains a fluid loss control agent selected from the group consisting of organic polymers, starches, and mixtures thereof. 
     
     
       12. The fluid of  claim 11  wherein shale hydration inhibition agent is selected from: 
       
         
           H 2 N—CH 2 CH 2 —O—CH 2 CH 2 —NH 2    
         
       
       
         
           H 2 N—CH 2 CH 2 CH 2 —O—CH 2 CH 2 —O—CH 2 CH 2 CH 2 —NH 2    
         
       
       
         
           NH 2 —CH 2 —CH(CH 3 )—(O—CH 2 —CH(CH 3 )) 8 —O—CH 2 —CH 2 —OCH 3    
         
       
       and mixtures of these. 
     
     
       13. A method of disposing of drill cuttings into a subterranean formation, the method comprising: 
       grinding the drill cuttings in a water-base fluid to form a slurry, wherein the water based fluid includes:  
       an aqueous based continuous phase and  
       a shale hydration inhibition agent having the formula:  
       
         
           H 2 N—R—{OR′} x —Y  
         
       
       wherein R and R′ are alkylene groups having 1 to 6 carbon atoms and  
       x is a value from about 1 to about 25, and  
       Y is an amine or alkoxy group, and wherein the shale hydration inhibition agent is present in sufficient concentration to reduce the swelling of shale, and  
       injecting said slurry into said subterranean formation.  
     
     
       14. The method of  claim 13  wherein x has a value of about 1 to about 10. 
     
     
       15. The fluid of  claim 13  wherein shale hydration inhibition agent is selected from: 
       
         
           H 2 N—CH 2 CH 2 —O—CH 2 CH 2 —NH 2    
         
       
       
         
           H 2 N—CH 2 CH 2 CH 2 —O—CH 2 CH 2 —O—CH 2 CH 2 CH 2 —NH 2    
         
       
       
         
           NH 2 —CH 2 —CH(CH 3 )—(O—CH 2 —CH(CH 3 )) 8 —O—CH 2 —CH 2 —OCH 3    
         
       
       and mixtures of these. 
     
     
       16. A method of disposing of drill cuttings that include a water-swellable shale, into a subterranean formation, the method comprising: 
       grinding the drill cuttings in a water-base fluid to form a slurry, wherein the water based fluid includes:  
       an aqueous based continuous phase and  
       a shale hydration inhibition agent selected from:  
       
         
           H 2 N—CH 2 CH 2 —O—CH 2 CH 2 —NH 2    
         
       
       
         
           H 2 N—CH 2 CH 2 CH 2 —O—CH 2 CH 2 —O—CH 2 CH 2 CH 2 —NH 2    
         
       
       
         
           NH 2 —CH 2 —CH(CH 3 )—(O—CH 2 —CH(CH 3 )) 8 —O—CH 2 —CH 2 —OCH 3    
         
       
       and mixtures of these, wherein the shale hydration inhibition agent is present in sufficient concentration to reduce the swelling of the shale, and  
       injecting said slurry into said subterranean formation.  
     
     
       17. The method of  claim 16  wherein the aqueous based continuous phase is selected from: fresh water, sea water, brine, mixtures of water with water soluble organic compounds and mixtures thereof. 
     
     
       18. A clear drilling fluid for use in drilling subterranean wells, said fluid comprising: 
       an aqueous based continuous phase;  
       a viscosifying agent and  
       a shale hydration inhibition agent having the formula:  
       
         
           H 2 N—R—{OR′} x —Y  
         
       
       wherein R and R′ are alkylene groups having 1 to 6 carbon atoms and x is a value from about 1 to about 25 and Y is an amine or alkoxy group, and wherein the shale hydration inhibition agent is present in sufficient concentration to reduce the swelling of shale.  
     
     
       19. The fluid of  claim 18  wherein the viscosifying agent is selected from the group consisting of organic polymers, starches, and mixtures thereof. 
     
     
       20. The fluid of  claim 18  wherein the aqueous based continuous phase is selected from: fresh water, sea water, brine, mixtures of water with water soluble organic compounds and mixtures thereof. 
     
     
       21. A fracturing fluid for use in stimulating subterreanean wells, said fluid comprising: 
       an aqueous based continuous phase;  
       a viscosifying agent and  
       a shale hydration inhibition agent having the formula:  
       
         
           H 2 N—R—{OR′} x —Y  
         
       
       wherein R and R′ are alkylene groups having 1 to 6 carbon atoms and x is a value from about 1 to about 25 and Y is an amine or alkoxy group, and wherein the shale hydration inhibition agent is present in sufficient concentration to reduce the swelling of shale. 
     
     
       22. The fluid of  claim 21  wherein the viscosifying agent is selected from the group consisting of organic polymers, starches, and mixtures thereof. 
     
     
       23. The fluid of  claim 21  wherein the aqueous based continuous phase is selected from: fresh water, sea water, brine, mixtures of water with water soluble organic compounds and mixtures thereof.